Direct electrochemical detection mechanism of ammonia in aqueous solution using Cu-decorated Si microelectrodes

Most of the reports on electrochemical ammonia detection with copper electrodes have been performed at pH 10 or higher. However, according to phase diagrams, no reactions take place between copper and ammonia under those conditions, qualifying such detec­tion of ammonia as indirect. This short paper deals with the detection of ammonia concen­tration in the micromolar range through a direct mechanism at pH 9, using a Cu-decorated microstructured Si electrode. The reaction mechanism is thoroughly studied.